Pneumatic, or vacuum, elevators can be installed in homes at a lower cost and in a fraction of the time than traditional residential elevators.
The elevators work on the principle that air will travel from an area of high to low pressure. The air in the area below the cab is kept at atmospheric pressure using a suction device. When the air pressure above the cab is lowered, the difference in pressure causes the cab to rise. When a valve in the upper part of the shaft lets air at atmospheric pressure into the low-pressure chamber, the difference in pressure lowers the cab.
The system operates without cables, pulleys, or pistons. Locking devices inside the shaft stop the cab at the top and bottom exactly at floor level. Since it is controlled by air pressure, rather than a mechanical system, starts and stops are very smooth. A braking system consisting of a diaphragm or piston on the roof of the cab activates if the tube above the cab suddenly returns to atmospheric pressure. Vacuum elevators are safe and reliable, since it is almost impossible to get stuck between floors or freefall. If the power goes out when the cab is descending, the elevator will automatically stop and lock at the next floor.
Vacuum elevators are transparent, self-supporting, constructed of aluminum and polycarbonate, and are quick to install. They are extremely light, have a capacity of up to 450 pounds, and take up only about one square-meter in area. They can work in almost any two- or three-story building, including non-conventional homes. They are a good option for existing homes, since they do not require excavation of a pit and hoistway. Maintenance costs are much lower than those for traditional residential elevators. Vacuum elevators use low amounts of energy when ascending and no energy when descending, making them a more affordable and environmentally-friendly option than other residential elevators.